Allow set the voting period to just 5 minutes (#10525)

* Add spec of PollValidator for #10190

* Raise fraction less than 1 second

* format

* simplify time initialize

spec/validators/poll_validator_spec.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe PollValidator, type: :validator do
+  describe '#validate' do
+    before do
+      validator.validate(poll)
+    end
+
+    let(:validator) { described_class.new }
+    let(:poll) { double(options: options, expires_at: expires_at, errors: errors) }
+    let(:errors) { double(add: nil) }
+    let(:options) { %w(foo bar) }
+    let(:expires_at) { 1.day.from_now }
+
+    it 'have no errors' do
+      expect(errors).not_to have_received(:add)
+    end
+
+    context 'expires just 5 min ago' do
+      let(:expires_at) { 5.minutes.from_now }
+      it 'not calls errors add' do
+        expect(errors).not_to have_received(:add)
+      end
+    end
+  end
+end